Minimum time before a tire can be used?
Minimum time before a tire can be used?
(OP)
Is there a minimum time after manufacturing before a tire can be used?
I am thinking for example for a heavy duty van such as Daimler Sprinter. If I get a brand new set of tires (and the tires, almost literally, just made, for example only 3 days old), is it safe to be fitted on a van loaded (lets say, 3 tonnes)? Or is there a minimum number of days or weeks before these tires can be used?
The reason I ask is because after the tire is moulded, I am guessing that the rubber will still be undergoing chemical changes before it reaches some kind of "equilibrium" state. Because of these changes I am also guessing that the components of the tire (sidewall, carcass, etc) will not be all perfectly set and if the tire is suddenly submitted to high strains such as the van conditions above mentioned, then the tires will be permanently "damaged" and not have the expected performance?
Gerardo
I am thinking for example for a heavy duty van such as Daimler Sprinter. If I get a brand new set of tires (and the tires, almost literally, just made, for example only 3 days old), is it safe to be fitted on a van loaded (lets say, 3 tonnes)? Or is there a minimum number of days or weeks before these tires can be used?
The reason I ask is because after the tire is moulded, I am guessing that the rubber will still be undergoing chemical changes before it reaches some kind of "equilibrium" state. Because of these changes I am also guessing that the components of the tire (sidewall, carcass, etc) will not be all perfectly set and if the tire is suddenly submitted to high strains such as the van conditions above mentioned, then the tires will be permanently "damaged" and not have the expected performance?
Gerardo





RE: Minimum time before a tire can be used?
Complex answer: When a tire comes out of the mold it is quite hot. While the rubber will continue to change, chemical reactions take place twice as fast for every 10°C rise in temperature. By the time it cools down it is ready to use.
The only exception to that is racing tires where heat cycling is sometimes called for - but this is not 100% the case even in racing tires, and certainly not true for street tires.
Just be aware of the fact that tires have a mold release substance on them and it may take some miles before it is completely worn off. Just take it easy for the first 100 or so miles.
RE: Minimum time before a tire can be used?
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Minimum time before a tire can be used?
In the motorcycle community (and likely other racing ones) there's been a long held belief that new tires need to be warmed up/scrubbed in before pushing them too hard in order to remove the mold release and/or heat cycle to leech out oils that will otherwise compromise traction.
The question is: Does anyone know why this isn't done at the factory? It seems strange that I need to "break in" a motorcycle street tire and an unnecessary safety risk. I'm sure there is a good reason, but I'm curious.
RE: Minimum time before a tire can be used?
Your typical consumer wouldn't buy such tires, because they'd be expensive, and because they'd look used.
Mike Halloran
Pembroke Pines, FL, USA
RE: Minimum time before a tire can be used?
Oh well.
RE: Minimum time before a tire can be used?
Norm
RE: Minimum time before a tire can be used?
Ah. First hand experience.
<conjecture>
I wonder if the tires were a little dry-looking from storage, and maybe somebody gave them a nice coat of Armor-All to dress them up. Now, _that_ stuff is slippery.
</conjecture>
If you didn't personally fit or witness fitting of the tires, you might inquire about the presence of tire dressing, and request that it not be applied to your new tires in the future. I might be inclined to word such a request more strongly. ... after ascertaining the facts, of course.
Mike Halloran
Pembroke Pines, FL, USA
RE: Minimum time before a tire can be used?
A little off-topic, but I don't even like the appearance of tire shines, to the point where I washed it off the tires on my wife's new Legacy (2.5GT) the day after we drove it home. On topic - I'd have noticed.
Norm
RE: Minimum time before a tire can be used?
I've certainly been caught out after 30 km of street use, in a Fiesta for goodness sake. Or at least, I doubt they dialled in oversteer intentionally!
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Minimum time before a tire can be used?
Rod
RE: Minimum time before a tire can be used?
Mold release: Part of what is going on here is that rubber compounds are made with antioxidants (AO's) and waxes to protect the tire - both in storage and in service. You do NOT want to have a tire heat cycled or scrubbed in until it is put in service.
Certainly the mold release and the waxes will cause the tire to be slippery at the very first, but they quickly get scrubbed off. The tire label story was a a good guide.
Heat cycling: Clearly that changes the rubber compound. I've seen NASCAR go back and forth. I suspect it has to do with the properties of the tread compound and how they change over time. I think it would be easy to understand that new tires will change fairly rapidly at first - particularly if they are street or street based.
Also clearly, dedicated race tires - NASCAR or F1 - where it is known that the tires will either be used that weekend or scrapped - might not be built with waxes and AO's. I suspect that more generalized race tires are built with minimal AO's.
I think the operative word here is that new tires should be used gently at first until their operating parameters are better known. And awareness that these change over time is important, too!
RE: Minimum time before a tire can be used?